From 6df3e7b1620372cf89b31eb5ff007fc4d1e721cf Mon Sep 17 00:00:00 2001 From: Akira Hatanaka Date: Sat, 12 Nov 2011 02:34:50 +0000 Subject: [PATCH] Implement Mips64's handling of byval arguments in LowerCall. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144452 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/Mips/MipsISelLowering.cpp | 112 ++++++++++++++++++++++++--- 1 file changed, 100 insertions(+), 12 deletions(-) diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp index 9ac2a6d332c..f30a7799a29 100644 --- a/lib/Target/Mips/MipsISelLowering.cpp +++ b/lib/Target/Mips/MipsISelLowering.cpp @@ -2026,6 +2026,90 @@ WriteByValArg(SDValue& ByValChain, SDValue Chain, DebugLoc dl, MachinePointerInfo(0), MachinePointerInfo(0)); } +// Copy Mips64 byVal arg to registers and stack. +void static +PassByValArg64(SDValue& ByValChain, SDValue Chain, DebugLoc dl, + SmallVector, 16>& RegsToPass, + SmallVector& MemOpChains, int& LastFI, + MachineFrameInfo *MFI, SelectionDAG &DAG, SDValue Arg, + const CCValAssign &VA, const ISD::ArgFlagsTy& Flags, + EVT PtrTy, bool isLittle) { + unsigned ByValSize = Flags.getByValSize(); + unsigned Alignment = std::min(Flags.getByValAlign(), (unsigned)8); + bool IsRegLoc = VA.isRegLoc(); + unsigned Offset = 0; // Offset in # of bytes from the beginning of struct. + unsigned LocMemOffset = 0; + + if (!IsRegLoc) + LocMemOffset = VA.getLocMemOffset(); + else { + const unsigned *Reg = std::find(Mips64IntRegs, Mips64IntRegs + 8, + VA.getLocReg()); + const unsigned *RegEnd = Mips64IntRegs + 8; + + // Copy double words to registers. + for (; (Reg != RegEnd) && (ByValSize >= Offset + 8); ++Reg, Offset += 8) { + SDValue LoadPtr = DAG.getNode(ISD::ADD, dl, PtrTy, Arg, + DAG.getConstant(Offset, PtrTy)); + SDValue LoadVal = DAG.getLoad(MVT::i64, dl, Chain, LoadPtr, + MachinePointerInfo(), false, false, false, + Alignment); + MemOpChains.push_back(LoadVal.getValue(1)); + RegsToPass.push_back(std::make_pair(*Reg, LoadVal)); + } + + // If there is an argument register available, copy the remainder of the + // byval argument with sub-doubleword loads and shifts. + if ((Reg != RegEnd) && (ByValSize != Offset)) { + assert((ByValSize < Offset + 8) && + "Size of the remainder should be smaller than 8-byte."); + SDValue Val; + for (unsigned LoadSize = 4; Offset < ByValSize; LoadSize /= 2) { + unsigned RemSize = ByValSize - Offset; + + if (RemSize < LoadSize) + continue; + + SDValue LoadPtr = DAG.getNode(ISD::ADD, dl, PtrTy, Arg, + DAG.getConstant(Offset, PtrTy)); + SDValue LoadVal = + DAG.getExtLoad(ISD::ZEXTLOAD, dl, MVT::i64, Chain, LoadPtr, + MachinePointerInfo(), MVT::getIntegerVT(LoadSize * 8), + false, false, Alignment); + MemOpChains.push_back(LoadVal.getValue(1)); + + // Offset in number of bits from double word boundary. + unsigned OffsetDW = (Offset % 8) * 8; + unsigned Shamt = isLittle ? OffsetDW : 64 - (OffsetDW + LoadSize * 8); + SDValue Shift = DAG.getNode(ISD::SHL, dl, MVT::i64, LoadVal, + DAG.getConstant(Shamt, MVT::i32)); + + Val = Val.getNode() ? DAG.getNode(ISD::OR, dl, MVT::i64, Val, Shift) : + Shift; + Offset += LoadSize; + Alignment = std::min(Alignment, LoadSize); + } + + RegsToPass.push_back(std::make_pair(*Reg, Val)); + return; + } + } + + unsigned MemCpySize = ByValSize - Offset; + if (MemCpySize) { + // Create a fixed object on stack at offset LocMemOffset and copy + // remainder of byval arg to it with memcpy. + SDValue Src = DAG.getNode(ISD::ADD, dl, PtrTy, Arg, + DAG.getConstant(Offset, PtrTy)); + LastFI = MFI->CreateFixedObject(MemCpySize, LocMemOffset, true); + SDValue Dst = DAG.getFrameIndex(LastFI, PtrTy); + ByValChain = DAG.getMemcpy(ByValChain, dl, Dst, Src, + DAG.getConstant(MemCpySize, PtrTy), Alignment, + /*isVolatile=*/false, /*AlwaysInline=*/false, + MachinePointerInfo(0), MachinePointerInfo(0)); + } +} + /// LowerCall - functions arguments are copied from virtual regs to /// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted. /// TODO: isTailCall. @@ -2112,6 +2196,22 @@ MipsTargetLowering::LowerCall(SDValue InChain, SDValue Callee, SDValue Arg = OutVals[i]; CCValAssign &VA = ArgLocs[i]; MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT(); + ISD::ArgFlagsTy Flags = Outs[i].Flags; + + // ByVal Arg. + if (Flags.isByVal()) { + assert(Flags.getByValSize() && + "ByVal args of size 0 should have been ignored by front-end."); + if (IsO32) + WriteByValArg(ByValChain, Chain, dl, RegsToPass, MemOpChains, LastFI, + MFI, DAG, Arg, VA, Flags, getPointerTy(), + Subtarget->isLittle()); + else + PassByValArg64(ByValChain, Chain, dl, RegsToPass, MemOpChains, LastFI, + MFI, DAG, Arg, VA, Flags, getPointerTy(), + Subtarget->isLittle()); + continue; + } // Promote the value if needed. switch (VA.getLocInfo()) { @@ -2157,18 +2257,6 @@ MipsTargetLowering::LowerCall(SDValue InChain, SDValue Callee, // Register can't get to this point... assert(VA.isMemLoc()); - // ByVal Arg. - ISD::ArgFlagsTy Flags = Outs[i].Flags; - if (Flags.isByVal()) { - assert(IsO32 && - "No support for ByVal args by ABIs other than O32 yet."); - assert(Flags.getByValSize() && - "ByVal args of size 0 should have been ignored by front-end."); - WriteByValArg(ByValChain, Chain, dl, RegsToPass, MemOpChains, LastFI, MFI, - DAG, Arg, VA, Flags, getPointerTy(), Subtarget->isLittle()); - continue; - } - // Create the frame index object for this incoming parameter LastFI = MFI->CreateFixedObject(ValVT.getSizeInBits()/8, VA.getLocMemOffset(), true);